Tamworth could still be warm for much of the day on Friday with the mercury set to reach a high of 28 degrees and a low of nine despite cloud cover and light winds in the evening.

Saturday looks like the last chance to get outdoor activities out of the way with a maximum of 27 degrees, light winds and mostly sunny weather.

There's a 50 per cent chance of rain and a thunderstorm hitting town on Sunday with 20km northeasterly winds in the morning.

BOM meteorologist Helen Kirkup said temperatures could drop five to 10 degrees within a couple of hours as a result of the trough.

"We have quite a broad, low-pressure trough through the inland of Australia and as this moves over we are expecting to see some fairly gusty winds and the potential for thunderstorms in the far west of the state on Saturday," she said.

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"As this slowly moves east we will see central parts of NSW start to see some rainfall during Sunday and there is that risk in some areas of sever thunderstorms with this system as it comes through.

"It does have the potential to create some decent thunderstorms."

The BOM will continue to monitor the situation and release warnings if necessary.